At the conclusion of “The Road to Woodstock” — a memoir by the prime organizer of the famous rock festival published on the eve of its 40th anniversary — the author says the road from Woodstock led to President Barack Obama’s election.

“During a time of great challenges in America, a community grew out of Woodstock,” Michael Lang writes. “Stemming from similar values and aspirations, a sense of possibility and hope was born and spread around the globe. . . .You see it in the many green movements, in grassroots organizations like MoveOn, and in what some pundits have called a Woodstock moment, the election of our first African-American president. As Jimi Hendrix recast the national anthem (at a Woodstock performance) in the mud, he gave voice to a future where a Barack Obama could bring change to America and hope to the world.”

Whether you think Woodstock led to Obama’s victory, or that the Republicans’ mishandling of the economy and war in Iraq had more to do with it, it’s a provocative reading of the festival’s legacy — his festival’s legacy — by Lang.

This book could use more such deep thinking about Woodstock’s meaning, not just to American culture at large but to the rest of Lang’s personal and professional life. (He has remained in the entertainment business.) Instead it has lots of details about how the fest went down — some interesting, too much dryly mundane.

Lang was only 24, a Brooklyn-born longhaired, laid-back head shop owner in Miami, who had staged one money- losing fest there, when he hatched Woodstock. He and three partners staged the outdoor Woodstock Music and Art Fair in White Lake/Bethel, N.Y., for upward of 400,000 young, countercultural-leaning fans during Aug. 15-17, 1969. The attendees overwhelmed the site, capturing the nation’s attention by braving rainy weather, massive traffic jams and lack of adequate food and shelter to hear the new, psychedelized rock music of the day.

They took solace in the peaceful communal spirit (often aided by drugs) that came from listening to 31 musical acts, among them heroes like Joan Baez, the Jefferson Airplane, Grateful Dead, Janis Joplin and Country Joe and the Fish. (There were also a few odder choices, like rock-revivalists Sha Na Na.)

Hendrix closed the show on the morning of the 18th with a set that included his startling deconstruction and revision of “The Star-Spangled Banner.” Overall, Lang says, Woodstock was a rare historical moment of mass utopian joy, even though there were three deaths.

But the fest lost money, in part because Lang’s Woodstock Ventures had to make it free to handle the arrival of so many kids without tickets. But an Oscar-winning documentary and its soundtrack album helped make the Woodstock enterprise valuable.

Lang’s information on how the festival occurred, including the minutiae about the financial, legal and technical challenges, is thorough. This is interesting to a point, but the travails are pretty well known by now. The town of Wallkill, N.Y., where the event was supposed to be held, canceled it at the last moment, creating a panic until the producers found a dairy farmer, Max Yasgur, willing to rent his land.

The author’s account of all this wrangling is anticlimactic now. He does reveal that Yasgur got a $50,000 fee plus $75,000 to be held in escrow in case of damages.

It’s especially worth noting that the relative peacefulness amid Woodstock’s chaos wasn’t by accident. Lang worked hard to hire an experienced security force that wouldn’t antagonize a crowd that gate-crashed, used drugs and sometimes shed a few more clothes than public decency laws allowed.

Before Woodstock, Lang visited the June 27-29 Denver Pop Festival, where police in riot gear fought with rowdy youths and sprayed the crowd with tear gas trying to clear the entrance. “There I ran head-on into everything I wanted to avoid at Woodstock,” Lang writes.

Most interesting in “Road to Woodstock” is how Lang made the musical choices he did for Woodstock — who he didn’t want to perform (Rolling Stones, who would overwhelm the other acts); who he wanted but couldn’t get (Bob Dylan, The Moody Blues); who wanted to play but couldn’t (John Lennon); who did play but acted like jerks (the Who, whose leader, Pete Townshend, clobbered radical activist Abbie Hoffman with his guitar on stage).

There are also strange connections. One of Lang’s partners, Artie Kornfeld, got a fest-saving, lucrative film deal from Warner Bros. Pictures because its president had once booked the Cowsills, a family- member, teen-pop band (“Indian Lake”) that Kornfeld had once managed. Strangest of all, Lang wanted to close the festival with cowboy star Roy Rogers singing “Happy Trails.” He would have followed Hendrix, but turned it down.

Since Woodstock performances made stars out of many musicians (Richie Havens, Ten Years After, Melanie, Joe Cocker, Santana), there is also a fascinating “there but for fortune” aspect to this book.

For instance, one person who never got to play (and never had much of a career) was the one who inspired the whole thing — a bluesy folk singer named Ellen McElwaine. Lang saw her perform at a small outdoor concert in the rural, artsy New York community of Woodstock after moving there in summer 1968. He thought the event so cool he got the idea for a bigger event in the area.

Because Lang waited so long to write this, he needed some help. Co-author Holly George-Warren conducted a lot of secondary interviews with Woodstock-related figures that are interspersed oral-history style throughout the book. She is excellent at research, as she showed in her own Gene Autry biography, “Public Cowboy No. One,” but as often as not that material gets in the way here.

And to get insight from the musicians and others who were at Woodstock, the book uses older published material, including excerpts from some, like Jerry Garcia and activist Hoffman, who are long dead.

I’m sure Lang could have filled this book himself if he’d fleshed out his remembrances and ideas about Woodstock’s legacy more.

Denver Pop Culture Con is being postponed until November as the city of Denver prepares to potentially turn the Colorado Convention Center, where the event is held, into a temporary medical facility to treat coronavirus patients.